The bouncing and jiving started with a few players on the far end of the USC bench.

Then those on the kickoff team and the coaches about to address them joined in. Before long, the entire Trojans sideline Saturday at Sam Boyd Stadium had transformed into a dance circle early in the second quarter at the Royal Purple Las Vegas Bowl.

By the end, the reserves who spent the whole game motivating the team might have wound up as exhausted as the stars who blazed the Bulldogs for hundreds of yards. The Trojans had ample reason for celebration all afternoon.

USC rocked its way to a 45-20 victory over Fresno State in the 2013 Las Vegas Bowl.

What happened to the version of the Trojans many speculated were left lifeless by enduring their second coaching change of the year? Never showed up. This was a team arriving hungry, acting borderline maniacal to achieve its mission of a 10th victory in a season many wrote off as broken months ago.

“We said, ‘Are we going to use it as an excuse to be on our third straight head coach, were we going to let up, or were we going to say we weren’t going to fail today?’” interim coach Clay Helton explained his pregame message. “These guys did a tremendous job.”

Scoring touchdowns on three of its first four possessions set the sideline off in a frenzy that lasted the rest of the game. Kessler, a sophomore, was the spark.

He found All-American Marqise Lee streaking in the end zone for a 10-yard touchdown to open the game before firing 40 yards to a wide-open Nelson Agholor minutes later.

Kessler bombed another pass on the next scoring drive, placing a 17-yard spiral where only the tightly covered Agholor could get to it in the back of the end zone. Even the official right next to the play was surprised.

He originally ruled it an incompletion before further review overturned the play into a touchdown.

“We said going into this game that we would fire every bullet that we had,” Helton said. “We told our offense, defense and special teams that. We wanted to be ultra-aggressive.”

Kessler converted a fourth-down attempt on USC’s first drive, but the biggest sign of its all-out attack approach came right after going ahead 7-0. Helton stuck to his plans of attempting an onside kick, and the Trojans appeared to recover.

But they drew a late flag for kick-catch interference, which gave the Bulldogs the ball on the 33-yard line and enabled a quick touchdown. The nine-yard connection from quarterback Derek Carr to receiver Isaiah Burse would bring Fresno State’s only points of a first half they lost 35-6.

“Unfortunately we weren’t able to keep possession of the ball,” USC cornerback Josh Shaw said of the onside kick. “But as players, we love to know that the coaches have that trust in you to dial up an aggressive game plan.”

A Bulldogs offense putting up 570 yards per game could only muster 254 against the Trojans.

“Our guys were ready to go,” Carr said. “There wasn’t a lack of focus on either side of the ball in practice or anything. The focus was there. USC just beat us.”

And beat them badly. Javorius Allen trucked over Fresno State defenders regularly once USC had a large lead, finishing with 93 yards and two touchdowns on 26 carries.

Lee, a junior, gave a fine performance in what was presumably his last game at USC with seven catches for 118 yards.

“These last eight practices were his best of the entire year and you could see it,” Helton said. “The way he practiced, he played tonight. We were extremely excited to see that from him. We knew he was going to do big things tonight.”

Kessler hoisted the Most Valuable Player trophy after passing for a career-high 344 yards and four touchdowns, the latter setting a Las Vegas Bowl record. By halftime, reports spread that new USC coach Steve Sarkisian would retain Helton as his offensive coordinator next season.

There was no indication whether the team’s bowl performance had any bearing on the decision, but it couldn’t have hurt. In the Las Vegas Bowl, the Trojans’ execution was only surpassed by their energy.